The development and increased commercial use of LEDs in all kinds of lighting device has led to a desire to be able to control the power level and hence the brightness at which the devices operate. One reason for this is that modern LEDs can be exceptionally bright when run at full power. Such brightness may not be suitable for the task or mood for which the lighting device is needed, so it is useful to be able to select a more suitable brightness when required. Furthermore, when running at full power, LEDs can use substantial amounts of energy. Reducing the operating brightness also reduces the power consumption. This is especially useful when the lighting device battery-powered, as using reduced power can extend the life of the battery.
Hand held torches are a particular example of a lighting device where brightness control is used. One reason for this is the wide variety of situations or conditions in which one may use a torch. A known torch of this type is the EDC Ultimate Flashlight manufactured by HDS Systems, Inc. This flashlight permits the user to select the brightness of four levels which can be accessed quickly during use. The brightness of each level is selected from one of 19 or 20 preset (non-adjustable) levels. The user can also select from a number of preset flashing modes if they are desired instead of a steady beam. In this example, selection and setting is achieved by manipulating the flashlight's operating button. The flashlight is arranged to distinguish between short ‘clicks’ and longer ‘presses’ of the button, and the user is able to access and change the optional features described above by entering different sequences of clicks and/or presses. However, the limited vocabulary of sequences and their complexity makes the options on the flashlight difficult and time-consuming to set.